I've had a number of front bags including Rivendell and Acorn. I've also tried out Arkel and Ostrich. All those bags have issues for me. The Arkel and the randonneur bags were heavy, the other bags looked nice but the closures, mounting and arrangement of pockets were annoying. I decided I wanted a light bag, about a 6 liter capacity with one large compartment, a carrying strap and an easy mounting system. The Ortlieb Classic is pretty close to ideal for me. I can carry fairly bulky items in it and it is light and tough and the Klick-Fix mount is so easy to undo that I automatically take the bag with me whenever I leave the bike....even for a few seconds. I carry stuff in it that I cannot afford to lose of have stolen

Gloves
Balaclava
Umbrella
Rain jacket
Cable lock
Wallet
Sunglasses
iPhone
Charger, cables and backup battery
Headlamp
Leatherman Juice
Maps
First aid kit
Wash kit
Food in a large Ziploc bag (3 Gallon size)
A couple of sodas